Cross-sectional serological study to estimate foot-and-mouth disease virus non-structural protein antibodies in randomly sampled small ruminants and pigs in Haryana during 2019 and 2020

Foot-and-mouth disease (FMD) is highly contagious and affects various cloven-hoofed animals including cattle, buffalo, sheep, goat and pig. This study investigates the prevalence of foot-and-mouth disease virus (FMDV) non- structural protein antibodies (NSP-Abs) as an indicator of past or recent FMDV exposure in small ruminants and pigs sampled randomly in Haryana state of India, during 2019 and 2020. Serum samples were collected from 440 goats, 440 sheep and 216 pigs in 2019, and 436 goats, 436 sheep and 218 pigs in 2020, representing all 22 districts of Haryana. Samples were tested using an in-house indirect 3AB3 NSP ELISA. The results revealed positive NSP- Ab rates of 26.36% in goats, 13.18% in sheep, and 5.09% in pigs in 2019, and 24.54% in goats, 14.22% in sheep, and 13.30% in pigs in 2020, indicating their previous exposure to FMDV. In contrast, the NSP-Ab prevalence in the bovine population of Haryana was lower, reported at 7.3% (179/2450) in 2019 and 4.4% (173/3930) in 2020. This indicates a higher rate of FMDV circulation in goats, sheep and pigs compared to bovines in the state during the study period. Given this reversal in infection dynamics, there is an urgent need to strengthen intensive active surveillance of FMD in the bovine population by screening oropharyngeal fluid samples to follow-up NSP reactors. Additionally, implementing routine six-monthly vaccination of small ruminants and pigs along with active surveillance in Haryana is recommended to control FMD and reduce disease transmission.